Cabtbidge fuse



Feb. 19, 1929.

H. R. COOK ET AL CARTRIDGE FUSE Original Filed Nov. 11, 1925 Patented Feb. 19, 1929.

UNITED STATES m ss.

PATENT OFFICE.

HER-BERT RAY COOK AND CHESTER A. JOHNSON, OF CHICAGO, ILLINOIS, ASSIG-NORS TO CHICAGO JEFFERSON FUSE & ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A COR- IORATION OF ILLINOIS.

CARTRIDGE FUSE.

Application filed November 11, 1925, Serial No. 68,277. Renewed July 9, 1928.

More particularly the invention relates to a renewable cartridge fuse of the knife blade type wherein the blades are incorpo rated in a terminal blade unit which is bodily removable from the casing, it being the general object of the invention to provide in such a. fuse a new'and improved terminal blade unit especially adapted for use where is desirable to join the blades by a plurality of fusible elements so as to afford in creased current carrying capacity.

Another object of the invention is to pro vide a terminal blade unit of an improved construction, wherein the terminal blades are secured in rigid alinement by means of a detachable insulating bridge section so constructed and related to the blades as to permit free access to the fusible links in re newing the latter.

In pursuance of the foregoing objects, we aim to provide a renewable cartridge fuse having a suitable casing a terminal blade unit comprising a pair of contact blades joined by one or more fusible links and secured in rigid alinement by means of a detachable insulating bridge section, and means to secure said terminal blade unit detachably in said casing.

Further objects and advantages will become apparent as the description proceeds.

In the drawings,

Figure 1 is a longitudinal view of the preferred form of the invention partly in central section.

Fig.v 2 is a similar view taken in a plane at right angles to that of Fig. 1.

Fig. 3 is an elevational view of the terninal blade unit, with a portion of the in sulating bridge broken away.

Fig. 4 is a. section taken approximately along line i4t of Fig. 1.

Fig. 5 is a section in the plane of line 5-5 of Fig. 2 with the end cap removed.

Fig. 6 is a section in the plane of line 66 of Fig. 52 with the end cap removed.

Fig. 7 is a perspective view of one of the clips of the bridge section.

For purposes of disclosure, we have illustrated in the drawings and will hereinafter describe in detail the preferred embodiment of the invention, with the understanding that we do not intend to limit the invention to the particular construction and arrangement shown, it being contemplated that various changes may be made by those skilled in the art withoutdeparting from the spirit and s ope of the appended claims.

In the form herein illustrated the invention embodies a casing comprising an insulating tube 1 of fibre or other suitable ma terial having metallic heads or bushings 2 suitably secured at the opposite ends thereof as by means of the screw threads 3 and rivets l. The heads have outer end walls or webs 5 forming alined non-circular apertures 6 therein, these apertures being herein shown as equal in size and shape and as having four straight ed ed sides at right angles to each other. Two of the webs have opposed notches 7 therein offset from the central portion of the webs as shown in Figs. 4, 5 and 6.

The terminal blade unit in the preferred form illustrated comprises a pair'of knife blade terminals 8 and 8, joined by one or more fusible elements 9 and having plates 10 and 10 fixed transversely thereon, the blades being secured rigidly in spaced relation by means of an insulating bridge section to be presently described. The knife blades are provided with opposed shoulders 11 formed on the edges thereof, the inner portions 12 of the blades being narrower than the outer or terminal portions. The plates 10 and 10 which are apertured to permit insertion of the inner portions 12 of the blades, are secured against the shoulders by any suitable means. These shoulders eXtend beyond the edges of the plates and abut the outer side of the webs 5 of the heads when positioned axially of the casing (see Figs. 5 and 6 wherein the position of the terminal portions of the blades is shown in dotted outline), to prevent inward movement of the blade therein, as shown for the left hand end in Fig. 1, the plates 10 and 10" then be ing positioned within the apertures 6 and in the planes of or flush with the webs The plate 10 is adapted to fit snugly in and to close the aperture of one head as shown in Fig. 6, to hold the blade 8 central thereof and against rotary movement in the easing. The plate 10 fits snugly against three of the straight sides of the aperture of the other head to partly close said aperture and to prevent rotary movement of the blade 8 in that head when the blade is central thereof, said plate being narrower on one side of the blade to permit lateral movement of the lating members or bars 13 and 13 secured rigidly togetherand adjacent the edges of the blades by means of two lJ-shaped channel like metallic clipsle positionedbetween the insulating membersat their opposite ends and secured thereto. by means of rivets 15. These clips as shown in Fig. 7, have the upright portions 16 extended longitudinally and turned outwardly at the top edgesto provide ledges-or flanges 17 against-which the insulatingimembers abut to prevent a pivotal move ment of the-clip about the rivets and to obtain a rigidstructin'e. The intermediate portions 18 are flat and of a length to permit the inner portions 12 of the terminal blades to fit snugly withinthe U. Suitable fasteningdevices may be provided to secure the clips to the ter' minal blades, such devices beingherein shown as comprisingbolts 19 passing through apertures in the clips and blades, and-nuts 20, the apertures preferably beingrso positionedthat when the'fastening. devices are tightened the ends of the bridge section abut the plates 10 and10 The fusible links 9 may be connected directly'to the terminal blades and independent-ly of th'e b ridge'section, as for example, by means of bolts 21 passing through apertures in'the blades and links-thev adjacent links being. spaced apart by the terminal blades, or washers 22; Nuts-23 engaging the. bolts 21serve to clamp-the links and blades together, washers 245" being, positioned between the outer links and the bolt heads and nuts.

As herein illustrated; the terminal blade unit is held centrally in the casingzandaga-inst longitudinal movement by means comprising the shoulders 11. the webs 5, apair of washers 25' and two screw-threaded end caps26 which engage correspondingly screw-threaded portions of theheads 2. These washers have slots therethrongh adapted to admit the terminal portions of the knife blades so-that the washers maybe slidon the blades andup against the webs 5 andpl-ates 10 and 10. As shown 111 Figs. land 2:for the left hand end of the fuse, hen the end caps 26 are screwed tightly on the heads 2, the shouldeis of the blades abut the webs 5, .and the washers-25 contact the plates and'heads to holdthe: blades cenan in the casing. and against longitudinal" and transversemovement; the plates 10and 10' then fitting snugly in the apertures of theliea-ds to prevent rotary movement of the. bladesln thecas ng. The washer25 and end cap 26. for. one. end of the fuse. are. preferably retained permanently on one terminal blade as by means of projecting portions 27 thereon,

thesepermitting rotary movement of the cap 8 by means of the projecting portions 27 of the blade. The blade 8 may then be moved transversely of the casing until theshoulders 11 on the blade register with the notches 7 after which the entire terminal blade unit may be withdrawn to the right, the said knife blade 8 passing through the notches 7 in both heads and the plate 10 through the apertures 6. The terminal-blade unit now being entirely removed from thecasing, the nutsQS may be loosened readily and the ends of the blown fuse linkremovechthe links 9 preferably having transverse open-ended slots 28 therein shown in Fig; 1) through which the bolts 21 are adapt-ed to pass, and the insulating member 13 being approximately the same width as the thickness of the blades to permit the links adjacent the blade to be removed without considerable movement of the nuts 23 on the bolts. After inserting a new link'or links the nut'23'may be tightened and the fuse reassembled by ins'ertingthe 8 entering between the notches 7 of the heads.

When the plate 10 enters the aperturefi the blade 8 is central of the'casing and the shoulders 11 of the blade abut the webs 5 to prevent further longitudinal'mo'vement inwardly. Then the wider terminal portion of the blade '8 has passed-through the notches 7 in the left handhead thuspermittinga transverse movement of that blade'to position it centrally of the head as shown'in Fig. 5. with the shoulders 11 abutting-the outward'sides of the webs 5. The washers 25'1n'ay then he slid on the blades and against" the plates 10 andlO and the caps 26 screwed tightly on the heads;

For properlyventing the casing" any suitable means may be provided to supplement the passages formed between the parts herein shown due to their relative positions or loose ly fitting interengagement. v

From the foregoing. itwill be apparent thatwehav'e provided an improved cartridge fuse embodying-a terminal blade unit'ofsimplitied construction which is detachable from the casing andbodily removable therefrom for purposes of renewing the fusible links. The insulatingbridge section isalso ofunitary construction to permit of readyrep-lacement should it in any way-become damaged; and isparticularly adapted to secure the terminal b lades in-rigid alineme'nt the insulatthe clips secured totlie blades in a manner fuse of the pre adapted to prevent pivotal movement of the clips relative to the insulating members and blades.

The division of the insulating portion of the bridge section into members adjacent the opposite edges the blades, add on to providing a rigid structure, permits the use of a plurality of fusible links such is required in tuses of large capacity, and renders them readily accessible for renewal purposes.

Ti e claim as our inve 'on 1. ii renewable cartridge fuse havi combination, a tubular casing, a te blade unit comprising a pair of knife blade terminals, a plurality of l usible elements detachably joining said blades, an insul ing bridge section securing said blades in spaced relation, said bridge section cinnprising a pair of laterally spaced insulatingmembers adjacent the edges of said blaees, a pair of U-shaped metal clips linen between the adjacent ends or said members to secure them in and detachably secured thereto,

said spaced relation, and means to secure said clips to said blades, said clips being adapted to engage three sides of said blades and tvvo sides of said insulating members to prevent relative pivotal movement, and means to secure. said terminal blade unit in said casing.

52. A terminal blade unit for cartridge 'fuses comprising in combination, a pair of knite blades, a fusible element joining said blades and an insulating bridge section securing said blades in spaced relation, said bridge section comprising a pair of U-shaped clips secured to and fitting snugly against three sides of said blades and having outwardly extending longitudinal flanges thereon, and a pair of hit orally spaced insulating members secured at their opposite ends to said clips and against said flanges.

3. A terminal blade unit for cartridge fuses comprising, in combination, a pair of knife blades, a fusible element joining said blades and detachably secured thereto, and an insulating bridge section securing said blades section includpositioned longiand adjacent the in spaced relation, said bridge ing tWO insulating members tudinally of the said blades side edges thereof.

l. A terminal 1)" do unit for cartridge fuses comprising. in combinatimr, two blades. :1 fusible element delachabl joining said blades, and an insulating bridge section scoured to and holding said blades in spaced relation. said bridge section comprising a pair of insulating bars disposed along edges of said blades.

5. In a terminal blade unit for cartridge fuses, the combination of a pair of knife blade terminals, a fusible element detachably joining said blades, and an insulating bridge. section securing said blades in spaced relation, said bridge section including an insulating opposite comprising a pair of insulating members in lateral y spaced relation, and pair of metallic clips positioned between and secured to said members djacent their opposite ends.

7. An insulating bridge section for can tridge fuses con'iprising, in combination, a pair of laterally spaced insulating members, and a pair of U-shaped channel like :1 .tallic clips of substantial length positioned bet veen and secured to said members and at the oppo site ends thereoi with the leg portions ot the clips engaging the said member), said ll portions having outwardly turned lim l udinal flanges also a axing said members.

8. A terminal b \LC unit for renewable car tridge fuses cou'iprisin in combination, a pair of knife blade terminals, a metallic plate fixed transverse If, on each blade, a fuse element detr liably joining said blade, an it :ulating bri lge section adapted to secure said blades in spaced relation, said bridge section comprising a pair of laterally spaced insulating members positioned adjacent the opposite eoges of said blades, and metallic clips secured to and oining the adjacent ends of said insulatin members, and means to secure I id clips to said blades and in abutment with said plates.

9. A terminal blade unit for renewable cartridge fuses comprising, in combination, a pair of knife blade terminals, a metallic plate fixed transversely on each blade, a fuse element detachably joining said blades, an in sulating bridge section adapted to secure said blades in spaced relation, said bridge section comprising a pair of laterally spaced insulating members positioned adjacent the opposite edges ot said blades, and a pair of U- shaped metallic clips secured to and joining the adjacent ends of said insulating members, said clips being adapted to engage two sides of said blades and two sides of said insulating member and means to secure said clips in engagement with said blades and in abutment. with said plates.

10. A terminal blade unit for cartridge fuses comprising, in combination, two terminal blades, a fusible element joining said blades and detachably secured thereto, and an insulating bridge section securing said blades in spaced relation, said bridge section including an insulating bar positioned longitudinally of said blades and adjacent the side edges thereof.

11. A terminal blade unit for renewable cartridge fuses comprising, in combination, a

pair of terminal blades, a fusible element detachably joining said blades, and a bridge section securing said blades in spaced relation, said bridge section comprising an insulating member and a pair of metallic clips, said clips being of an L-shaped section and adapted to engage a side and an edge of the said knife blades, one leg of each clip having an outturned flange extending longitudinally of the clip, means to secure said insulating member to said legs and in engagement with said flanges, and means to secure said clips to said blades.

12. An insulating bridge section for renewable knife-blade cartridge fuses, comprising an insulating bar adapted to be positioned longitudinally of and adjacent the side edges of the knife blades, and a pair of metallic clips, one secured to each end of said bar and adapted to be attached to said knife blades.

13. A terminal blade unit for car ridge fuses, comprising a pair of knife blade terminals, a plurality of fusible elements joining said blades, means to secure the opposite ends of said elements to said blades, and an insulating bridge adapted to secure said blades in spaced relation, said bridge comprising an insulating bar having a metallic clip secured to each end thereof, and means to secure said metallic clips detachably to said blades independently of said fuse element securing means.

14. A terminal blade unit for renewable cartridge fuses comprising, in combination, a pair of knife blade terminals, a metallic plate fixed transversely on each blade, a fuse element detachably joining said blades, an insulating bridge section adapted to secure said blades in spaced relation, said bridge section comprising apair of laterally spaced insulating members positioned adjacent the opposite edges of said blades, and a pair of metallic clips secured to and joining the adjacent ends of said insulating members, said clips being adapted to engage two sides of said insulating members, and means to secure said clips in engagement with said blades and in abutment with said plates.

15. A terminal blade unit for renewable cartridge fuses comprising, in combination, a pair of terminal blades, a fusible element detachably joining said blades, and a bridge section securing said blades in spaced relation,

said bridge section comprising an insulating member and a pair of metallic clips, said clips having oortions of an l -shaped section adapted to engage two sides of said insulating member, means to secure said insulating member to said clips, and means to secure said clips to said blades.

In testimony whereof we have hereunto affixed our signatures. HERBERT RAY COOK. CHESTER A. JOHNSON 

